'The Underground' is a single player mod for half Life 2: Episode 2. It puts you into the role of Duglas Melbourne, as he ventures to a place close to him, transformed by the after math of a communist take over on his home country. But instead of finding out more about the war, he finds out more about death, and where people went in the once secret 'Undeground'.
A stressful ambient track. Builds very slowly and is loop-able.